All chains can do this though. We have to remember crypto is inter-subjective. A chain only has value when other people agree it has value. Eth Classic still ex

All chains can do this though. We have to remember crypto is inter-subjective. A chain only has value when other people agree it has value. Eth Classic still exists, it even has some value for whatever reason. Block chains are about crowd consensus, and any block chain community can decide to hard fork. I don't think its possible to prevent that on a block chain.